Protractor



Sg Z, 1932. T, QWD

PROTRCTOR Filed July l5. 192B INV Wm f W@ ATTO RN EY.

V WITNESS:

Patented Sept. 20, 1932 UNITED.

THOMAS DOWD, OF NEW YORK, N. Y.

IPROTRACTOR 5 Application ined :my 1e, 1928. serial No. 293,062.. j

This invention relates to improvements'in protractors for determining the angularity between the adjacent ends of two pipes to enable the accurate bending andfitting of a' 5 pipe section therebetween.

` rlhe primary object of the invention residesin a protractor for use upon jointed rules and which may be quickly attached to .ff the rule adjacent any desired joint therein 10 depending upon the space which the jointed sections of therule must bridge in taking a measurement between two angularly disposed-pipes. Y Another `object is to provide a protractor for measuring .rules-by which the jointed sectionsA of the rule may be held against movementuafter the rule sections have been bent to the desired angle, to prevent any'miscal- -g culation when bending a part `at the angle to conform tothe angularity of the adjusted rule sections. j

Still another object is to enable the protractor to be used with ointed rules of practically any type so that the user may employ any suitable jointed rule he may have.

A further object is the provision of a protractor which is simple of construction, easy to apply to jointedvrules now in use,.and .by

the use of which accurate calculations may 30 be determined.

With these and other objects in View, the invention resides in certain novel constructionand combination and arrangement *of 'rf parts, the essential features of which are hereinafter fully j described, vvare particularly pointed out in the appended claims, and are illustrated in the accompanying drawing, in which Figure 1 is a side elevation of a jointed rule with my improved protractor in position thereon and showing the same in use.

Figure 2 is an enlarged detail top plan view of a pair of jointed rule sections with j my improved protractor in applied position thereon. l

Figure 3 is an edge elevation of the same.

Figure 4 is is a vertical transverse` sectional View on the line 4-4 of Figure 2.

Figure 5 is a detail perspective view of the adjusting clamp.

Figure 6 is a plan view of a slightly modie'd forni. v .l Y Referring to the drawing by reference characters, the numeral 10 designates my im-- proved protractor in its entirety which ijs. 55

shown in the preferred form asfapplied to one of the pivoted joints 11 of a carpenters folding. rule 12'. The rule 12 is of the usual well-known construction and is graduated to Y indicate inches and fractions thereof as-at 13.. 60:

The protractor 10 comprises in this .instance an arcuate shape plate 111 which is slightly more than 18.0.to provide a flXed jaw 15 at one'end thereof and which jaw is provided witha liange or lip 16. for over- 65 lying one of the edges of the rule sectionsto which the protractor is attached. lRising from the jawl isla threaded stud 17 over which a movable clamping jaw 18is applied,v the same having a lip 19 Vfor overlying the 70 other edge of the rule section and being'disposedopposite thelip 16;. The jaw 18 ispro= vided vwithan opening 20 of a larger 'diameterthan the lthreaded stud and through, which the stud extends, ,while threaded to 7'5 and surrounding thestud within the open.- ing 2O is a clamping nut'21. The nut 21 has an annular bevelled orpconical surface 22 which extends into the opening 201 when screwed down and engages'the walls'of' the'so same to wedge therewithto hold'said movable jaw 18 in clamping position. Y The arcuate plate 14 in this instance' is graduated along its'outer edge for 180 'as at 28 and is provided withanarcuateshape slot 24 which extends slightly` beyond theA graduations at one end'. Movable in the slot is an adjustmentclamp 25 which includes 'a jaw 26 having a square stud 27 rising there.- from and which terminates in a reduced threaded shank 28. The jaw 26 underlies-a rule section while the squared lstu-d 27 extends in the slot to prevent turningV ofthe clamp. |The threaded shank 28 proj ects-above the top face lof the 'arcuate plate to threaded', ly receive a clamping nut 29 bywhich the, jaw may be drawninto clamping engagement with the underside of one lof the rule secH tions.

` in Figur" 1 ofthe drawing, I have inuslo trated one use of my invention wherein A designates a horizontal pipe and B the terminating end of an angular pipe to which the pipe A is adapted to be joined. The protractor 1() is mounted on the rule adjacent one of the hinge joints so that the axis of the arcuate shaped plate aligns with the pivotal axis of the rule sections C and D. The radius of the protractor being known, the pivotal axis of the rule sections is set that distance from the edge of jaw 15, thus aligning the respective axes of the arcuate plate and rule; thus enabling practicallyany jointed rule to be used withthe plate 14. The attaching clamp consisting of the aws 15 and 1,8and clamping nut 21, is applied to the rule section C while the arcuate shaped plate 14 overlies the rule section D as clearly shown in Figures 1 and 2. The rule is opened at the joint 11 between rulesections C and D and bent to an angle to bridge the space between the Vadjacent ends ofthe pipesV A and B, the rule being placed against the pipes as shown in Figure 1. However, before bending the rule sections C and D, a reading is taken with the saidrule sections in alignment or as shown in dotted lines in Figure 2. The reading is taken at'the point offregistration of the upper edge E of 'the rule section D with the graduations 23 on Ythe arcuate plate. For example, if the edge E registered with 8Oo when the sections are in co-extended position, and after bending to thevangle desired, theupper edge E registered with the graduation` reading 135,the difference between 80 and 135.0 will represent the deviation or amount of bend of the 'pipe to be bent and i fitted into .the space between the pipeV A and B.4 When' the rule sections C and D have Y been swung to adjusted position, the adjusting clamp 25 is tightened to hold the sections lagainst accidental movement.` i

i, From the foregoing description taken in connection Vwith the v accompanying drawing,

'l it will be seen that thek exactmeasurement of an angular pipemay bedetermined to fit the spaced terminating ends of a pair of pipes to be connected. .Y

In Figure 6 of the drawing, the construction of the protractor 10 is identical to that hereinbefore described, butin this form I have shown the same applied to a steel draftsmans jointed 'ruleBO on which anv indicating mark 31 is provided for use in connection with the graduations in lieu of the straight edge of one of the rulejoint sections as def scribedin the preferred form.

. -While I have described what I deem to be the most desirable embodiment of my invention, it is 'obvious vthat many` of the details maybe varied without in any way departing from the spirit of my invention, and I therefore do not limit myself tothe exact details ofconstructionherein set forth. nor toV anything less than the whole of my invention limited only by the appended claims.

W'hat is claimed as new is 1. A protractor for attachment to a jointed rule comprising an arcuate shaped graduated plate, clamping means by which said plate may bef'ixedly attached to one jointed rule section to overlie the next adjacent rule section, adjustable clamping means carried by said plate for holding the rule sections in an adjusted position; said clamping means including means permitting the rule to slide to position with the axes of the rule joint and protractor plate inV alignment, and said adjustable clamping means including an underlying jaw portion, whereby the next adjacent rule section-may be inserted between said jaw portion andsaid graduated plate, said graduated plate having a slotted portion and said adjustable clamping means including a portion nonrotatably securable, in adjusted position in said slot. Y 'i 2. A protractor for attachment to a jointed rule comprising, in combination, an arcuate shaped plate having a stationary j awat one end thereof, means including -a movable clamping j aw for co-actionv with the 4stationary jaw to iixedly supportv said arcuate shaped plate upon one rule section, said arcuate shaped plate having an arcuate shaped slot therein, and ajclamping device movable along said slot for engagement with the next adjacent jointed rule section forclamping said arcuate platefthereto when yin adjusted 1 signature. Y

' THOMAS DQWD.V`

Y 13oV 

